Large aperture zoom lens system

ABSTRACT

A large-aperture zoom lens system comprising a first focusing lens unit having a positive focal length, a second variator lens unit having a negative focal length, a third compensator lens unit having a negative focal length and a fourth relay lens unit, said fourth lens unit consisting of a front subunit comprising at least one negative lens component and a rear subunit comprising at least two positive lens components. Said lens system comprises a small number of lens elements, and has a short total length, a long back focal distance and favorably corrected aberrations.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a photographing zoom lens system, andmore specifically to a compact large-aperture zoom lens system suitedfor use with electronic photographing cameras, television cameras or thelike.

(b) Description of the Prior Art

Zoom lens systems have hitherto been adopted as lens systems for almostall the electronic photographing cameras, television cameras or thelike. So much considerations have not been taken for compactness andmanufacturing cost of these zoom lens systems though they are moreexcellent than the lens systems for use with cameras using Leica size offilm in that the former lens systems have aperture ratios higher thanF/2.0 and varifocal ratios higher than 3. However, in the recentcircumstance where popular photographing cameras adopt the electronicpick-up devices, compactness and reduction of manufacturing cost arerequired for optical systems for use with said popular photographingcameras. Therefore, demands are increasing for zoom lens systemscomprising a front lens component with a small diameter, having a shorttotal length and using a small number of lens elements.

Since the lens systems of this type have a characteristic as one ofcomponent parts consisting a photographing systems and the weight ofsuch lens system is restricted for the purpose of performing automaticfocusing and power zooming at low power consumption, it is desirable toadopt a rear focusing system in place of the focusing system by shiftingthe first lens group, reduce number of lens groups to be shifted forzooming and use a relay lens system prolonging the back focal distance.

There are many photographing zoom lens systems which have apertureratios higher than F/2.0 and varifocal ratios higher than 3. However,there has conventionally been known no zoom lens system that can satisfythe three requirements of compactness (short total length and smalldiameter of the front lens component), low manufacturing cost(especially, a small number of lens elements) and a long back focaldistance, and has performance high enough to cope with the futurepossible increase in number of picture elements on the image pick-updevice. Especially, there has been obtained no high performance lenssystem that is designed for a back focal distance having a valueexceeding 0.9 times of geometrical mean f_(S) of the shortest focallength f_(W) and the longest focal length f_(T) of said lens system.Lens systems having a long back focal distance are required since it isnecessary to interpose various optical members between the final lenssurface of the system and photographing surface. Therefore, ratiobetween back focal distance f_(B) and f_(S) must be increased as focallength of the lens system becomes shorter. Japanese published examinedpatent applications No. 40852/80, No. 32387/73, etc. disclosed zoom lenssystems comprising small numbers of lens elements and having short backfocal distances, but took no considerations to prolong the back focaldistance.

The conventional zoom lens system performed focusing by shifting thefront lens groups having the large diameters and heavy weights. However,the focusing system of this type had a defect to allow remarkablevariations of aberrations, especially spherical aberration and chromaticaberration, especially when the lens systems are focused on objectslocated at short distances on the long focal length sides of the lenssystems. Further, the focusing system of this type has another defectthat diameter of the front lens component must be increased since thelower rays are eclipsed by the front lens component when the lens systemis focused on an object located at a short distance. In order toeliminate these defects, it is preferable to adopt the rear focusingsystem. Automatic focusing is made possible at low power consumption byadopting the rear focusing system. As a zoom lens system using the rearfocusing system, there has been known the one disclosed by Japanesepublished unexamined patent application No. 78513/82.

In the lens system disclosed as Embodiment 1, however, aberrations,especially astigmatism, are remarkably varied when said lens system isfocused on an object located at a short distance. The lens systemdisclosed as Embodiment 2 has a small aperture ratio of F/5.6.Therefore, this conventional example does not satisfy theabove-mentioned requirements of an aperture ratio larger than F/2.0 anda back focal distance longer than 0.9f_(S). In addition, performance ofthe said lens system is not so high since it allows remarkablevariations of aberrations, especially spherical aberration and coma,when it is focused on an object located at a short distance.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a large-aperturezoom lens system having a field angle of 15° to 45°, varifocal ratio of3, an F number on the order of F/2.0, high performance, a short totallength and a long back focal distance.

Another object of the present invention is to provide a large-aperturezoom lens system allowing little variations of aberrations, requiring nolarge a diameter for the front lens component owing to no insufficientlight intensity caused by eclipse of the lower rays, being compatiblewith a simple focusing mechanism and having a rear focusing mechanismdesirable for automatic focusing.

The zoom lens system according to the present invention comprises avarifocal subsystem consisting of a first lens unit I having a positivefocal length and being immovable for varying focal length of said lenssystem, a second variator lens unit II having a negative focal lengthand being movable for varying focal length of said lens system, and athird compensator lens unit III having a negative focal length and beingmovable for compensating variation of image position mainly caused byvarying focal length of said lens system, and a fourth relay lens unit.Said fourth lens unit is composed of a front subunit comprising at leastone negative lens component and at least two positive lens components,and a rear subunit comprising at least two positive lens components.

The present invention has succeeded in reducing manufacturing cost andweight of the zoom lens system by designing the fourth relay lens unitin such a manner that it comprises a small number of lens components,i.e., 6 or 7 lens components. Further, the lens system according to thepresent invention has a long back focal distance so as to permitinterposing various optical members between the final surface of thelens system and image surface. Moreover, the lens system according tothe present invention is capable of favorably correcting aberrationssuch as spherical aberration and coma though it comprises a small numberof lens components and has a long back focal distance. Speakingconcretely, back focal distance has been prolonged by arranging negativelens component on the image side in the front subunit of the fourth lensunit so as to diverge rays with said negative lens component. In orderto favorably to correct aberrations in the lens system comprising thesmall number of lens components and having the long back focal distance,a positive lens component having a surface with a small radius ofcurvature on the image side is arranged before said negative lenscomponent. The reason for this arrangement is that, if a positive lenscomponent having strongly positive refractive power on the image side isarranged before said negative lens component, the surface havingstrongly positive refractive power is arranged closely to the surfacehaving strongly negative refractive power, and rays are subjected to aconflicting refracting action within a short distance, thereby making itdifficult to correct spherical aberration.

The zoom lens system according to the present invention has the backfocal distance prolonged by arranging the negative lens component havingstrongly negative refractive power at a position relatively on the imageside as described above. If the negative lens component has too strongdiverging function, however, it will be difficult to correct sphericalaberration and coma. For this reason, the zoom lens system according tothe present invention is designed in such a manner that distance lbetween the rear focal point of said lens system to the object sidesurface of said negative lens component satisfies the followingcondition (1):

    1.5f.sub.IV <l<2.2f.sub.IV                                 ( 1)

wherein the reference symbol f_(IV) represents focal length of thefourth lens group.

If l is shorter than the lower limit of the condition (1), the negativelens component will have too small radii of curvature on both thesurfaces (especially radius of curvature on the object side surface),thereby allowing higher order spherical aberration and higher order comato be easily produced. If the upper limit of the condition (1) isexceeded, in contrast, total length of the lens system as a whole willbe prolonged.

Further, it is desirable for prolonging back focal distance of the lenssystem to select airspace D between front subunit IVa and rear subunitIVb of the fourth lens unit within the range defined below:

    0.14f.sub.IV <D<0.5f.sub.IV                                ( 2)

If the airspace D is narrower than the lower limit 0.14f_(IV) of thecondition (2), it is necessary for prolonging the back focal distance ofthe lens system to increase the powers of the front subunit IVa and rearsubgroup IVb of the fourth lens unit, thereby allowing higher orderspherical aberration and higher order coma to be easily produced. Inaddition, it is impossible to reserve an airspace sufficient forfocusing by shifting the rear subunit as described later. If D exceedsthe upper limit 0.5f_(IV) of the condition (2), total length of the lenssystem as a whole is apt to be prolonged.

Though the lens system according to the present invention can be focusedby sifting its first lens unit, said lens system adopts the systemranging from the first lens component to the front subunit of the fourthlens unit designed as an afocal system in order to suppress variationsof aberrations when said lens system adopts rear focusing method bysifting the rear subunit in the fourth lens group.

In order to make applicable the above-described focusing method usingthe rear subunit IVb, the system ranging from the first lens unit I tothe front subunit IVa of the fourth lens unit (the system indicated by Ain the drawings) is designed as an afocal system in the zoom lens systemaccording to the present invention. Further, in order to accomplish oneof the objects of the present invention to provide a zoom lens systemhaving a back focal distance longer than 0.9f_(S), total focal lengthf_(A) of said system A (the system ranging from the first lens unit I tothe front subunit IVa of the fourth lens unit) must satisfy thefollowing condition (3):

    -0.3<f.sub.W /f.sub.A <0.3                                 (3)

wherein the reference symbol f_(W) represents the shortest focal lengthof the zoom lens system as a whole.

If f_(W) /f_(A) is smaller than the lower limit of the condition (3),spherical aberration is apt to be overcorrected when the zoom lenssystem is focused on an object located at a short distance. If the upperlimit of the condition (3) is exceeded, in contrast, sphericalaberration is apt to be undercorrected and, at the same time, it will bedifficult to obtain a back focal distance exceeding 0.9f_(S).

When the zoom lens system according to the present invention is focusedby shifting the rear subgroup IVb of the fourth lens unit as describedabove, the rear subunit IVb should desirably comprise lens components ina number as small as possible. So far as the lens system satisfies thecondition (3), it is practicaly useable even when the rear subunitconsist only of a single-element lens component. When variation ofastigmatism is taken into consideration, howwever, the rear subunit IVbshould desirably consist of two or three positive lens components. Inorder to minimize variation of astigmatism, it is desirable to designthe positive lens component arranged on the extreme object side in saidrear subunit IVb so as to have a shape concentrical with the exit pupil.For this purpose, the positive lens component should desirably have animage side surface with a negative radius of curvature which is small inabsolute value. Further, the positive lens component arranged on theextreme image side should have a concave object side surface with aradius of curvature smaller than that on the image side surface thereof.This is advantageous also for correcting spherical aberration to obtaina zoom lens system having an aperture ratio exceeding F/2.0.

In order to prolong the back focal distance, it is advantageous todefine the upper limit of the conditions (3) as 0.2.

The present invention has been achieved to provide a zoom lens systemhaving performance sufficiently or excessively high enough for thecurrent or future electronic imaging device. For this purpose, the zoomlens system according to the present invention has adopted a compositionwherein a positive cemented doublet comprising a negative meniscus lenselement and a biconvex lens element, and a positive single-elementmeniscus lens component are arranged in the order from object side inthe first lens unit I, a negative single-element meniscus lens componentand a negative cemented doublet comprising a biconcave lens element anda positive lens element are arranged in the second lens unit II, and atleast one negative lens component is arranged in the third lens unit.

Further, selected for the front subunit IVa of the fourth lens group isa composition comprising three to five lens components; a positive lenscomponent, a positive lens component and a negative lens component, or apositive lens component, a positive lens component, a negative lenscomponent and a positive lens component, or a positive lens component, apositive lens component, a positive lens component and a negative lenscomponent. Furthermore, selected for the rear subunit IVb is acomposition comprising two positive lens component, or a negative lenscomponent and two or three positive lens components.

The zoom lens system according to the present invention is so designedas to satisfy the following conditions (4) and (5):

    2.5f.sub.W <f.sub.I <3.5f.sub.W                            ( 4)

    -1.2f.sub.W <f.sub.II <-0.8f.sub.W                         ( 5)

wherein the reference symbol f_(I) represents focal length of the firstlens group I and the reference symbol f_(II) designates focal length ofthe second lens unit II.

The condition (4) defines focal length f_(I) of the first lens unit I.If the focal length f_(I) is longer than the upper limit of thecondition (4), total length of the varifocal system will be prolonged.If the focal length is shorter than the lower limit of the condition(4), in contrast, the radius of curvature is minimized on each lenssurface in the first lens unit I and, each lens must be undesirablythickened for obtaining the required lens diameter. In addition,aberrations, especially spherical aberration and coma, will beaggravated too much for favorable correction.

The condition (5) defines focal length f_(II) of the second lens groupII. If f_(II) is shorter than the upper limit of the condition (5), itwill be desirable for shortening the total length of the varifocalsubsystem but will allow remarkable variations of aberrations to becaused by zooming. If f_(II) is longer than the lower limit of thecondition (5), in contrast, the total length of the varifocal subsystemwill be prolonged.

When the first lens group I and second lens unit II have too strongpowers respectively, the offaxial ray will form a large angle with theoptical axis between both the lens units and the entrance pupil isdeviated toward the image side unless the airspace is narrowed betweenboth the lens units, thereby obliging to enlarge the diameter of thefront lens component of the first lens unit.

The zoom lens system according to the present invention is capable ofcorrecting aberrations more favorably when it is designed so as tosatisfy the following condition (6) through (9):

    1.7<n.sub.4                                                ( 6)

    0.05<n.sub.6 -n.sub.5                                      ( 7)

    1.6<n.sub.5                                                ( 8)

    13<ν.sub.5 -ν.sub.6                                  ( 9)

wherein the reference symbol n₄ represents refractive index of thenegative meniscus lens component arranged in the second lens unit II,the reference symbols n₅ and ν₅ designate refractive index and Abbe'snumber respectively of the biconcave lens element arranged in the secondlens unit II, and the reference symbols n₆ and ν₆ denote refractiveindex and Abbe's number respectively of the positive lens elementarranged in the second lens unit II.

The conditions (6) and (8) define refractive indices of the negativelens elements respectively arranged in the second lens unit II. Thesenegative lens elements are made of materials having large refractiveindices or so designed as to have large radii of curvature on thesurfaces thereof mainly for minimizing spherical aberration and preventvariations of aberrations from being caused by shifting the second lensunit. If these conditions are not satisfied, aberrations will be variedremarkably.

The condition (7) has been adopted for imparting an aberrationcorrecting function to the cemented surface of the negative cementeddoublet arranged in the second lens unit. If the difference between therefractive indices of the two lens elements of the cemented doublet istoo small to satisfy the condition (8), the aberration correctingfunction of the cemented surface is weakened and aberrations must becorrected with the other lens components.

The condition (9) has been adopted for correcting chromatic aberration.If the condition (9) is not satisfied, chromatic aberration will bevaried remarkably by zooming. Speaking more concretely, paraxialchromatic aberration will be undercorrected at short wavelengths andlateral chromatic aberration will be overcorrected as the zoom lenssystem is varied from its wide position to tele position.

For enhancing performance of the zoom lens system according to thepresent invention, it is desirable to design it so as to satisfy thefollowing conditions (10) and (11):

    n.sub.IVn >1.78                                            (10)

    ν.sub.IVap <ν.sub.IVbp                               ( 11)

wherein the reference symbol n_(IVn) represents a mean refractive indexof the negative lens elements arranged in the fourth lens unit IV, thereference symbol ν_(IVap) designates a mean Abbe's number of thepositive lens elements arranged in the front subunit IVa of the fourthlens unit, and the reference symbol ν_(IVbp) denotes a mean Abbe'snumber of the positive lens elements arranged in the rear subunit IVb ofthe fourth lens unit.

In a zoom lens system such as the one disclosed by the presentinvention, the greatest cause for producing higher order sphericalaberration and higher order coma is attributable to the small radii ofcurvature on the negative lens elements arranged in the fourth relaylens group. Therefore, these negative lens elements should desirablyhave large refractive indices. If the above-mentioned condition (10) isnot satisfied, the negative lens elements will have too small a radii ofcurvature to prevent higher order spherical aberration and higher ordercoma from being produced.

The condition (11) has been adopted for correcting lateral chromaticaberration. If the condition (11) is not satisfied, lateral chromaticaberration will be undercorrected though longitudinal chromaticaberration can be corrected favorably.

In order to further prolong the back focal distance of the zoom lenssystem according to the present invention while maintaining its shorttotal length and favorably corrected aberrations, it is desirable todesign it so as to satisfy the following conditions (12) through (14) asexamplified in Embodiments 1 through 5 described later.

    0.5f.sub.S <f.sub.IVa <1.6f.sub.S                          ( 12)

    0.42f.sub.S <|f.sub.IVan |<0.64f         (13)

    t.sub.B <0.45f.sub.S                                       ( 14)

wherein the reference symbol f_(IVa) represents focal length of thefront subunit IVa of the fourth lens group, the reference symbolf_(IVan) designates focal length of the negative lens component arrangedin said front subunit IVa and the reference symbol t_(B) denotesdistance as measured from the extreme object side surface to the extremeimage side surface of the rear subgroup IVb of the fourth lens unit.

If the focal length of the front subunit IVa of the fourth lens unit islonger than the upper limit of the condition (12), total length of therelay lens system will be prolonged. If the focal length is shorter thanthe lower limit of the condition (12), in contrast, back focal distanceof the zoom lens system as a whole is apt to be shortened.

If absolute value f_(IVan) of the focal length of the negative lenscomponent arranged in said front subgroup IVa is longer than the upperlimit of the condition (13), back focal distance of the zoom lens systemas a whole is apt to be shortened. If the absolute value is smaller thanthe lower limit of the condition (13), in contrast, zonal aberrationwill be remarkable produced and higher order aberrations are apt to beproduced.

The zoom lens system according to the present invention can be focusedby shifting the first lens unit I frontward. Further, said zoom lenssystem can be focused on an object located at a short distance byshifting the rear subunit IVb of the fourth lens unit frontward.

For focusing by the rear focusing method, it is desirable to arrange twoor three positive lens components in the rear subunit IVb of the fourthlens unit. In this case, said rear subunit should desirably satisfy theabove-mentioned condition (14). If the condition (14) is not satisfied,weight of said rear subunit will not be light and undesirable for rearfocusing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a sectional view illustrating the composition of the zoomlens system preferred as Embodiment 1 of the present invention;

FIG. 2 shows a sectional view illustrating the composition of the zoomlens system preferred as Embodiments 2 through 5 of the presentinvention;

FIG. 3 through FIG. 5 show sectional views illustrating the compositionsof the zoom lens systems preferred as Embodiments 6 through 8respectively of the present invention;

FIG. 6 through FIG. 8 show curves illustrating aberrationcharacteristics of the Embodiment 1 when it is focused on an objectlocated at infinite distance;

FIG. 9 through FIG. 11 show curves illustrating aberrationcharacteristics of the Embodiment 2 when it is focused on an objectlocased at infinite distance;

FIG. 12 through FIG. 14 show curves illustrating aberrationcharacteristics of the Embodiment 3 when it is focused on an objectlocated at infinite distance;

FIG. 15 through FIG. 17 show curves illustrating aberrationcharacteristics of the Embodiment 4 when it is focused on an objectlocated at infinite distance;

FIG. 18 through FIG. 20 show curves illustrating aberrationcharacteristics of the Embodiment 5 when it is focused on an objectlocated at infinite distance;

FIG. 21 through FIG. 23 show curves illustrating aberrationcharacteristics of the Embodiment 6 when it is focused on an objectlocated at infinite distance;

FIG. 24 through FIG. 26 show curves illustrating aberrationcharacteristics of the Embodiment 7 when it is focused on an objectlocated at infinite distance;

FIG. 27 through FIG. 29 show curves illustrating aberrationcharacteristics of the Embodiment 8 when it is focused on an objectlocated at infinite distance;

FIG. 30 through FIG. 32 show curves illustrating aberrationcharacteristics of the Embodiment 1 when it is focused on an objectlocated at short distance;

FIG. 33 through FIG. 35 show curves illustrating aberrationcharacteristics of the Embodiment 2 when it is focused on an objectlocated at a short distance;

FIG. 36 through FIG. 38 show curves illustrating aberrationcharacteristics of the Embodiment 3 when it is focused on an objectlocated at a short distance;

FIG. 39 through FIG. 41 show curves illustrating aberrationcharacteristics of the Embodiment 4 when it is focused on an objectlocated at a short distance;

FIG. 42 through FIG. 44 show curves illustrating aberrationcharacteristics of the Embodiment 5 when it is focused on an objectlocated at a short distance;

FIG. 45 through FIG. 47 show curves illustrating aberrationcharacteristics of the Embodiment 6 when it is focused on an objectlocated at a short distance;

FIG. 48 through FIG. 50 show curves illustrating aberrationcharacteristics of the Embodiment 7 when it is focused on an objectlocated at a short distance; and

FIG. 51 through FIG. 53 show curves illustrating aberrationcharacteristics of the Embodiment 8 when it is focused on an objectlocated at a short distance.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, numerical data will be described below as preferred embodiments ofthe zoom lens system according to the present invention:

    ______________________________________                                        Embodiment 1                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 145.4589                                                            d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 28.8038                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                                r.sub.3 = -124.4191                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.0380                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62045                                                                          ν.sub.3 = 38.12                                r.sub.5 = 194.2344                                                            d.sub.5 = 0.6000˜9.404˜16.075                                     r.sub.6 = 27.2667                                                             d.sub.6 = 1.0400                                                                             n.sub.4 = 1.78590                                                                          ν.sub.4 = 44.18                                r.sub.7 = 10.3892                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -15.8056                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.70154                                                                          ν.sub.5 = 41.21                                r.sub.9 = 13.5487                                                             d.sub.9 =  3.4000                                                                            n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = -92.7796                                                           d.sub.10 = 17.4871˜8.204˜2.434                                    r.sub.11 = -11.9646                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.71300                                                                          ν.sub.7 = 53.84                                r.sub.12 = -42.5665                                                           d.sub.12 = 1.2558˜1.725˜0.855                                     r.sub.13 = -85.6664                                                           d.sub.13 = 2.7002                                                                            n.sub.8 = 1.59270                                                                          ν.sub.8 = 35.29                                r.sub.14 = -17.9449                                                           d.sub.14 = 0.8553                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 21.1736                                                            d.sub.16 = 4.5115                                                                            n.sub.9 = 1.62230                                                                          ν.sub.9 = 53.20                                r.sub.17 = -27.2639                                                           d.sub.17 = 0.2100                                                             r.sub.18 = 14.3135                                                            d.sub.18 = 3.1600                                                                            n.sub.10 = 1.51742                                                                         ν.sub.10 = 52.41                               r.sub.19 = 115.7820                                                           d.sub.19 = 1.2000                                                             r.sub.20 = -25.5498                                                           d.sub.20 = 1.6617                                                                            n.sub.11 = 1.84666                                                                         ν.sub.11 = 23.88                               r.sub.21 = 15.2150                                                            d.sub.21 = 8.5579                                                             r.sub.22 = 2332.0237                                                          d.sub.22 = 4.2478                                                                            n.sub.12 = 1.51112                                                                         ν.sub.12 = 60.48                               r.sub.23 = -20.8501                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 33.8590                                                            d.sub.24 = 4.6445                                                                            n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                               r.sub.25 = -61.6882                                                           l/f.sub.IV = 1.852, D/f.sub.IV = 0.385, f.sub.W /f.sub.A = -0.197             f.sub.IVa /f.sub.S = 0.667, f.sub.IVan /f.sub.S = -0.456                      f.sub.I /f.sub.W = 3.061, f.sub.II /f.sub.W = -0.999, n.sub.4 = 1.78590       n.sub.6 - n.sub.5 = 0.14512, n.sub.5 = 1.70154                                ν.sub.5 - ν.sub.6 = 17.33, n.sub.IVn = 1.84666                          ν.sub.IVap - ν.sub.IVbp = -18.348, f.sub.B = 23.3                       t.sub.B /f.sub.S = 0.3722                                                     ______________________________________                                        Embodiment 2                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 84.1276                                                             d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 29.0902                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                                r.sub.3 = -273.1915                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.7778                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                                r.sub.5 = 203.0683                                                            d.sub.5 = 0.6000˜8.838˜14.867                                     r.sub.6 = 29.7145                                                             d.sub.6 = 1.0400                                                                             n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                                r.sub.7 = 11.3398                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -21.5403                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                                r.sub.9 = 15.9303                                                             d.sub.9 = 3.1000                                                                             n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = 1554.6274                                                          d.sub.10 = 12.9984˜5.073˜2.828                                    r.sub.11 = -14.7944                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                                r.sub.12 = -36.0319                                                           d.sub.12 = 4.9325˜4.598˜0.854                                     r.sub.13 = 50.3787                                                            d.sub.13 = 2.6753                                                                            n.sub.8 = 1.74950                                                                          ν.sub.8 = 35.27                                r.sub.14 = -29.8033                                                           d.sub.14 = 0.6469                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 20.2193                                                            d.sub.16 = 5.3125                                                                            n.sub.9 = 1.69350                                                                          ν.sub.9 =  53.23                               r.sub.17 = -440.8891                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -25.3662                                                           d.sub.18 = 1.4008                                                                            n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                               r.sub.19 = 18.0976                                                            d.sub.19 = 1.8984                                                             r.sub.20 = 104.9452                                                           d.sub.20 = 3.0000                                                                            n.sub.11 = 1.56873                                                                         ν.sub.11 = 63.16                               r.sub.21 = -33.8872                                                           d.sub.21 = 6.0137                                                             r.sub.22 = -1877.6563                                                         d.sub.22 = 3.6497                                                                            n.sub.12 = 1.48749                                                                         ν.sub.12 = 70.15                               r.sub.23 = -18.1673                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 27.7264                                                            d.sub.24 = 3.3156                                                                            n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.51                               r.sub.25 = -111.3847                                                          l/f.sub.IV = 1.642, D/f.sub.IV = 0.237, f.sub.W /f.sub.A = -0.221             f.sub.IVa /f.sub.S = 1.186, f.sub.IVan /f.sub.S = -0.507                      f.sub.I /f.sub.W = 2.996, F.sub.II /f.sub.W = -1.098, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350,                               ν.sub.5 - ν.sub.6 = 29.35, n.sub.IVn = 1.84666, t.sub.B /f.sub.s =      0.2928                                                                        ν.sub.IVap - ν.sub.IVbp = -19.597, f.sub.B = 23.3                       ______________________________________                                        Embodiment 3                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 82.8380                                                             d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 28.9584                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                                r.sub.3 = -243.9198                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.9601                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62374                                                                          ν.sub.3 = 47.10                                r.sub.5 = 203.8797                                                            d.sub. 5 = 0.6000˜8.647˜14.529                                    r.sub.6 = 29.0358                                                             d.sub.6 = 1.0400                                                                             n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                                r.sub.7 = 11.4509                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -21.5434                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.69680                                                                          ν.sub.5 = 55.52                                r.sub.9 = 16.1419                                                             d.sub.9 = 3.1000                                                                             n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = 327.0857                                                           d.sub.10 = 12.7201˜4.953˜2.849                                    r.sub.11 = -15.1829                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                                r.sub.12 = -38.3036                                                           d.sub.12 = 4.8880˜4.594˜0.854                                     r.sub.13 = 50.2085                                                            d.sub.13 = 2.6726                                                                            n.sub.8 = 1.76200                                                                          ν.sub.8 = 40.10                                r.sub.14 = -29.8907                                                           d.sub. 14 = 0.6433                                                            r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 20.1914                                                            d.sub.16 = 5.5367                                                                            n.sub.9 = 1.69680                                                                          ν.sub.9 = 55.52                                r.sub.17 = 2178.6990                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -25.1867                                                           d.sub.18 = 1.4025                                                                            n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                               r.sub.19 = 18.2541                                                            d.sub.19 = 1.8967                                                             r.sub.20 = 89.3959                                                            d.sub.20 = 3.0000                                                                            n.sub.11 = 1.62041                                                                         ν.sub.11 = 60.27                               r.sub.21 = -41.7577                                                           d.sub.21 = 6.1391                                                             r.sub.22 = -2160.7673                                                         d.sub.22 = 3.6490                                                                            n.sub.12 = 1.56873                                                                         ν.sub.12 = 63.16                               r.sub.23 = -20.1024                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 28.7875                                                            d.sub.24 = 3.3002                                                                            n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                               r.sub.25 =  -98.5889                                                          l/f.sub.IV = 1.752, D/f.sub.IV = 0.258, f.sub.W /f.sub.A = -0.253             f.sub.IVa /f.sub.S = 1.180, f.sub.IVan /f.sub.S = -0.508                      f.sub.I /f.sub.W = 2.951, f.sub.II /f.sub.W = -1.068, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.14986, n.sub.5 = 1.69680                                ν.sub.5 - ν.sub.6 = 31.64, n.sub.IVn = 1.84666, t.sub.B /f.sub.S =      0.2921                                                                        ν.sub.IVap - ν.sub.IVbp = -14.692, f.sub.B = 23.3                       ______________________________________                                        Embodiment 4                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 83.0383                                                             d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 29.1400                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                                r.sub.3 =  -253.150                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.6874                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                                r.sub.5 = 210.2929                                                            d.sub.5 = 0.6000˜8.638˜14.534                                     r.sub.6 = 30.3630                                                             d.sub.6 = 1.0400                                                                             n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                                r.sub.7 = 11.3638                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -21.4761                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                                r.sub.9 = 17.0207                                                             d.sub.9 = 3.1000                                                                             n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = 1069.1825                                                          d.sub.10 = 13.0418˜5.272˜2.789                                    r.sub.11 = -14.1675                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                                r.sub.12 = -36.2700                                                           d.sub.12 =  4.5289˜4.243˜0.854                                    r.sub.13 = 55.6389                                                            d.sub.13 = 2.6729                                                                            n.sub.8 = 1.74950                                                                          ν.sub.8 = 35.27                                r.sub.14 = -31.9536                                                           d.sub.14 = 0.6353                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 21.0858                                                            d.sub.16 = 5.0173                                                                            n.sub.9 = 1.69350                                                                          ν.sub.9 = 53.23                                r.sub.17 = -708.9650                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -27.0343                                                           d.sub.18 = 1.4021                                                                            n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                               r.sub.19 = 19.1950                                                            d.sub.19 = 1.9053                                                             r.sub.20 = 45.3739                                                            d.sub.20 = 3.0000                                                                            n.sub.11 = 1.56873                                                                         ν.sub.11 = 63.16                               r.sub.21 = -24.8871                                                           d.sub.21 = 6.6760                                                             r.sub.22 = -119.5541                                                          d.sub.22 = 3.6491                                                                            n.sub.12 = 1.48749                                                                         ν.sub.12 =  70.15                              r.sub.23 = -20.3750                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 28.5509                                                            d.sub.24 = 3.3004                                                                            n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                               r.sub.25 = -144.4908                                                          l/f.sub.IV = 1.863, D/f.sub.IV = 0.296, f.sub.W /f.sub.A = -0.016             f.sub.IVa /f.sub.S = 1.071, f.sub.IVan /f.sub.S = -0.539                      f.sub.I /f.sub.W = 2.939, f.sub.II /f.sub.W = -1.071, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 - ν.sub.6 = 29.35, n.sub.IVn = 1.84666, t.sub.B /f.sub.S =      0.2921                                                                        ν.sub.IVap - ν.sub.IVbp = -19.597, f.sub.B = 23.3                       ______________________________________                                        Embodiment 5                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 82.6129                                                             d.sub.1 =  1.1600                                                                            n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 29.2181                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                                r.sub.3 = -246.0953                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.4664                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                                r.sub.5 = 217.2658                                                            d.sub.5 = 0.6000˜8.516˜14.296                                     r.sub.6 = 34.0022                                                             d.sub.6 = 1.0400                                                                             n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                                r.sub.7 = 11.4972                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -20.9945                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                                r.sub.9 = 16.3829                                                             d.sub.9 = 3.1000                                                                             n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = 646.6454                                                           d.sub.10 = 12.8886˜5.006˜2.865                                    r.sub.11 = -14.2623                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                                r.sub.12 = -30.9806                                                           d.sub.12 = 4.5293˜4.484˜0.854                                     r.sub.13 = 50.7675                                                            d.sub.13 = 2.6656                                                                            n.sub.8 = 1.74950                                                                          ν.sub.8 = 35.27                                r.sub.14 = -30.6539                                                           d.sub.14 = 0.5921                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 19.1840                                                            d.sub.16 = 5.6618                                                                            n.sub.9 = 1.69350                                                                          ν.sub.9 = 53.23                                r.sub.17 = 3649.8366                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -24.4207                                                           d.sub.18 = 1.4073                                                                            n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                               r.sub.19 = 18.4904                                                            d.sub.19 = 3.8044                                                             r.sub.20 = 80.9804                                                            d.sub.20 = 3.0000                                                                            n.sub.11 = 1.56873                                                                         ν.sub.11 = 63.16                               r.sub.21 = -23.6744                                                           d.sub.21 = 4.3200                                                             r.sub.22 = -81.0091                                                           d.sub.22 = 3.6442                                                                            n.sub.12 = 1.48749                                                                         ν.sub.12 = 70.15                               r.sub.23 = -19.6764                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 28.3524                                                            d.sub.24 = 3.3101                                                                            n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                               r.sub.25 = -150.6774                                                          l/f.sub.IV = 1.771, D/f.sub.IV = 0.184, f.sub.W /f.sub.A = 0.010              f.sub.IVa /f.sub.S = 1.095, f.sub.IVan /f.sub.S = -0.505                      f.sub.I /f.sub.W = 2.894, f.sub.II /f.sub.W = -1.021, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 - ν.sub.6 29.35, n.sub.IVn = 1.84666, t.sub.B /f.sub.S =        0.2923                                                                        ν.sub.IVap - ν.sub.IVbp = -19.597, f.sub.B = 23.3                       ______________________________________                                        Embodiment 6                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 73.7446                                                             d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 29.0371                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62280                                                                          ν.sub.2 = 57.06                                r.sub.3 = -142.5789                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 29.7376                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                                r.sub.5 = 187.5263                                                            d.sub.5 = 0.6000˜8.158˜13.563                                     r.sub.6 = 761.2471                                                            d.sub.6 = 1.0400                                                                             n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                                r.sub.7 = 12.6032                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -19.9311                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                                r.sub. 9 = 14.4310                                                            d.sub.9 = 3.1000                                                                             n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = -537.6964                                                          d.sub.10 = 14.1628˜4.601˜3.099                                    r.sub.11 = -23.9031                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                                r.sub.12 = -49.2275                                                           d.sub.12 = 2.7690˜4.810˜0.854                                     r.sub.13 = 83.5278                                                            d.sub.13 = 2.6697                                                                            n.sub.8 = 1.73400                                                                          ν.sub.8 = 51.49                                r.sub.14 = -26.0629                                                           d.sub.14 = 0.6362                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 22.6910                                                            d.sub.16 = 3.1050                                                                            n.sub.9 = 1.69680                                                                          ν.sub.9 = 52.52                                r.sub.17 = 205.0173                                                           d.sub.17 = 1.2990                                                             r.sub.18 = -23.8698                                                           d.sub.18 = 1.0000                                                                            n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                               r.sub.19 = -199.2548                                                          d.sub.19 = 8.6005                                                             r.sub.20 = 152.2247                                                           d.sub.20 = 1.0000                                                                            n.sub.11 = 1.80518                                                                         ν.sub.11 = 25.43                               r.sub.21 = 26.2448                                                            d.sub.21 = 1.9319                                                             r.sub.22 = 120.3715                                                           d.sub.22 = 4.7975                                                                            n.sub.12 = 1.56873                                                                         ν.sub.12 = 63.16                               r.sub.23 = -19.9767                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 23.9392                                                            d.sub.24 = 4.6311                                                                            n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                               r.sub.25 = -72.0532                                                           l/f.sub.IV = 1.826, D/f.sub.IV = 0.346, f.sub.W /f.sub.A = 0.057              f.sub.I /f.sub.W = 2.717, f.sub.II /f.sub.W = -0.851, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 - ν.sub.6 =  29.35, n.sub.IVn = 1.82592                         ν.sub.IVap - ν.sub.IVbp = -13.15, f.sub.B = 0.95f.sub.S                 ______________________________________                                        Embodiment 7                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 73.4599                                                             d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 29.7582                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62280                                                                          ν.sub.2 = 57.06                                r.sub.3 = -143.3946                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 29.8304                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                                r.sub.5 = 193.5783                                                            d.sub.5 = 0.6000˜8.068˜13.415                                     r.sub.6 = -249.6054                                                           d.sub.6 = 1.0400                                                                             n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                                r.sub.7 = 13.4290                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -22.3190                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                                r.sub.9 = 13.6545                                                             d.sub.9 = 3.1000                                                                             n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = 395.1326                                                           d.sub.10 = 13.8889˜4.363˜3.225                                    r.sub.11 = -29.6120                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                                r.sub.12 = -74.5434                                                           d.sub.12 = 3.0371˜5.106˜0.854                                     r.sub.13 = 103.8661                                                           d.sub.13 = 2.6656                                                                            n.sub.8 = 1.72916                                                                          ν.sub.8 = 54.68                                r.sub.14 = -26.8147                                                           d.sub.14 = 0.5983                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 24.1544                                                            d.sub.16 = 3.7803                                                                            n.sub.9 = 1.69680                                                                          ν.sub.9 = 55.52                                r.sub.17 = 586.5944                                                           d.sub.17 = 1.2984                                                             r.sub.18 = -21.4118                                                           d.sub.18 = 1.0000                                                                            n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                               r.sub.19 = -175.5530                                                          d.sub.19 = 6.6556                                                             r.sub.20 = 78.7259                                                            d.sub.20 = 1.0000                                                                            n.sub.11 = 1.80518                                                                         ν.sub.11 = 25.43                               r.sub.21 = 33.7443                                                            d.sub.21 = 1.9815                                                             r.sub.22 = -76.7912                                                           d.sub.22 = 3.8000                                                                            n.sub.12 = 1.48749                                                                         ν.sub.12 = 70.15                               r.sub.23 = -17.6494                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 51.5682                                                            d.sub.24 = 3.0000                                                                            n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                               r.sub.25 = -54.5234                                                           d.sub.25 = 0.1500                                                             r.sub.26 = 33.6811                                                            d.sub.26 = 3.7439                                                                            n.sub.14 = 1.48749                                                                         ν.sub.14 = 70.15                               r.sub.27 = 306.4734                                                           l/f.sub.IV = 1.907, D/f.sub.IV = 0.284, f.sub.W /f.sub.A  = -0.078            f.sub.I /f.sub.W = 2.696, f.sub.II /f.sub.W = -0.844, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 - ν.sub.6 = 29.35, n.sub.IVn = 1.82592                          ν.sub.IVap - ν.sub.IVbp = -15.05, f.sub.B = 0.95f.sub.S                 ______________________________________                                        Embodiment 8                                                                  f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 73.1407                                                             d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                                r.sub.2 = 29.2813                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62280                                                                          ν.sub.2 = 57.06                                r.sub.3 = -142.5699                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 29.4855                                                             d.sub.4 = 5.6000                                                                             n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                                r.sub.5 = 188.5203                                                            d.sub.5 =  0.6000˜8.038˜13.370                                    r.sub.6 = -2148.9531                                                          d.sub.6 = 1.0400                                                                             n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                                r.sub.7 = 12.7344                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -19.2458                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                                r.sub.9 = 14.4976                                                             d.sub.9 = 3.1000                                                                             n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                                r.sub.10 = -336.4032                                                          d.sub.10 = 14.0324˜5.201˜2.643                                    r.sub.11 = -21.0833                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                                r.sub.12 = -51.2968                                                           d.sub.12 = 2.3119˜3.735˜0.854                                     r.sub.13 = 103.8053                                                           d.sub.13 = 2.6678                                                                            n.sub.8 = 1.72916                                                                          ν.sub.8 = 54.68                                r.sub.14 = -34.5149                                                           d.sub.14 = 0.6169                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 52.1018                                                            d.sub.16 = 3.3386                                                                            n.sub.9 = 1.69680                                                                          ν.sub.9 = 55.52                                r.sub.17 = -58.1766                                                           d.sub.17 = 0.1500                                                             r.sub.18 = 30.8549                                                            d.sub.18 = 3.0000                                                                            n.sub.10 = 1.69680                                                                         ν.sub.10 = 55.52                               r.sub.19 = 90.7813                                                            d.sub.19 = 1.3000                                                             r.sub.20 = -24.0593                                                           d.sub.20 = 1.0000                                                                            n.sub.11 = 1.84666                                                                         ν.sub.11 = 23.88                               r.sub.21 = -184.3586                                                          d.sub.21 = 5.8297                                                             r.sub.22 = 136.6332                                                           d.sub.22 = 1.0000                                                                            n.sub.12 = 1.80518                                                                         ν.sub.12 = 25.43                               r.sub.23 = 27.4732                                                            d.sub.23 = 1.9396                                                             r.sub.24 = 178.2704                                                           d.sub.24 = 4.7972                                                                            n.sub.13 = 1.56873                                                                         ν.sub.13 = 63.16                               r.sub.25 = - 19.8353                                                          d.sub.25 = 0.1342                                                             r.sub.26 = 27.9084                                                            d.sub.26 = 4.6096                                                                            n.sub.14 = 1.48749                                                                         ν.sub.14 = 70.15                               r.sub.27 = -64.6149                                                           l/f.sub.IV = 1.860, D/f.sub.IV = 0.255, f.sub.W /f.sub.A = 0.110              f.sub.I /f.sub.W = 2.685, f.sub.II /f.sub.W = -0.840, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 - ν.sub.6 = 29.35, n.sub.IVn = 1.82592                          ν.sub.IVap - ν.sub.IVbp = -11.415, f.sub.B = 0.95f.sub.S                ______________________________________                                    

wherein the reference symbols r₁, r₂, . . . represent radii of curvatureon the surfaces of the respective lens elements, the reference symbolsd₁, d₂, . . . designate thickensses of the respective lens elements andairspaces reserved therebetween, the reference symbols n₁, n₂, . . .denote refractive indices of the respective lens elements, the referencesymbols ν₁, ν₂, . . . represent Abbe's numbers of the respective lenselements, the reference symbol f designates focal length of the zoomlens system as a whole and the reference symbol f_(B) denotes back focaldistance of the zoom lens system as a whole.

Out of the embodiments described above, the Embodiment 1 has thecomposition shown in FIG. 1 wherein the front subunit IVa of the fourthlens unit comprises a positive lens component, a positive lenscomponent, a positive lens component and a negative lens component, andthe rear subunit IVb comprises two positive lens components. Aberrationcharacteristics of this embodiment are illustrated in FIG. 6 (wideposition), FIG. 7 (standard position) and FIG. 8 (tele position). Eachof the Embodiments 2 through 5 has the composition shown in FIG. 2wherein the front subunit IVa of the fourth lens unit comprises apositive lens component, a positive lens component, a negative lenscomponent and a positive lens component, and the rear subunit IVbcomprises two positive lens components. Aberration characteristics ofthese embodiments are illustrated in the following correspondence: theEmbodiment 2 in FIG. 9 (wide position), FIG. 10 (standard position) andFIG. 11 (tele position), Embodiment 3 in FIG. 12 (wide position), FIG.13 (standard position) and FIG. 14 (tele position), the Embodiment 4 inFIG. 15 (wide position), FIG. 16 (standard position) and FIG. 17 (teleposition) and the Embodiment 5 in FIG. 18 (wide position), FIG. 19(standard position) and FIG. 20 (tele position). In addition, theseembodiments are so designed as to satisfy the conditions (12), (13) and(14).

The Embodiment 6 has the composition shown in FIG. 3 wherein the frontsubunit IVa of the fourth lens unit comprises a positive lens component,a positive lens component having a convex surface with strong refractivepower on the object side and a negative lens component having a concavesurface with strong refractive power on the object side, whereas therear subunit IVb comprises a negative lens component, a positive lenscomponent and a positive lens component. Aberration characteristics ofthis embodiment are illustrated in FIG. 21 (side position), FIG. 22(standard position) and FIG. 23 (tele position).

The Embodiment 7 has the composition shown in FIG. 4 wherein the frontsubunit IVa of the fourth lens unit comprises a positive lens component,a positive lens component having convex surface with strong refractivepower on the object side and a negative lens component having a concavesurface with strong refractive power on the object side, whereas therear subunit IVb comprises a negative lens component, a positive lenscomponent, a positive lens component and a positive lens component.Aberration characteristics of this embodiment are illustrated in FIG. 24(wide position), FIG. 25 (standard position) adn FIG. 26 (teleposition).

The Embodiment 8 has the composition shown in FIG. 5 wherein the frontsubunit IVa of the fourth lens unit comprises a positive lens component,a positive lens component, a positive lens component having a convexsurface with strong refractive power on the object side and a negativelens component having a concave surface with strong refractive power onthe object side, whereas the rear subunit IVb comprises a negative lenscomponent, a positive lens component and a positive lens component.Aberration characteristics of this embodiment are illustrated in FIG. 27(wide position), FIG. 28 (standard position) and FIG. 29 (teleposition).

Each of the above-described embodiments can be focused by shifting thefirst lens unit frontward. However, these embodiments can adopt also therear focusing system. That is to say, the embodiments can be focused onobjects located even at a very short distance by shifting frontward therear subunit IVb in the fourth lens unit. For focusing these embodimentson objects located at a very short distance, the rear subunit IVb isshifted for the distances listed below:

                  TABLE                                                           ______________________________________                                                  f = 14    f = 24.25                                                                              f = 42                                           ______________________________________                                        Embodiment 1                                                                              0.181       0.538    1.627                                        Embodiment 2                                                                              0.183       0.542    1.633                                        Embodiment 3                                                                              0.186       0.552    1.672                                        Embodiment 4                                                                              0.173       0.510    1.505                                        Embodiment 5                                                                              0.173       0.510    1.499                                        Embodiment 6                                                                              0.174       0.512    1.499                                        Embodiment 7                                                                              0.175       0.518    1.539                                        Embodiment 8                                                                              0.176       0.516    1.510                                        ______________________________________                                    

Aberration characteristics at the wide position, standard position andtele position of these embodiments in the conditions where the zoom lenssystems are focused on objects located at a very short distance (1.2 m)are illustrated in FIG. 30 through FIG. 32, FIG. 33 through FIG. 35,FIG. 36 through FIG. 38, FIG. 39 through FIG. 41, FIG. 42 through FIG.44, FIG. 45 through FIG. 47, FIG. 48 through FIG. 50 and FIG. 51 throughFIG. 53 respectively.

As is understood from the foregoing detailed descriptions and thenumerical data set forth as the preferred embodiments, the presentinvention has succeeded in providing, by selecting an adequatecomposition for the fourth lens unit IV used as the relay lens system, azoom lens system designed for an aperture ratio of F/2.0, a zoomingratio of 3, field angles of 15° to 45° and favorably correctedaberrations regardless of a long back focal distance exceeding 0.9f_(S), and having performance high enough to cope with future increasein number of picture elements on imaging device. In addition, the zoomlens system according to the present invention can adopt also the rearfocusing system assuring very little variations of aberrations.

I claim:
 1. A large-aperture zoom lens system comprising a varifocalsubsystem comprising a first lens unit having a positive focal lengthand being immovable for varying focal length of said zoom lens system asa whole, a second variator lens unit having a negative focal length andbeing movable for varying focal length of the zoom lens system as awhole, and a third compensator lens unit having a negative focal lengthand functioning mainly for compensating variation of the image positioncaused by the variation of the focal length of said zoom lens system asa whole, and a relay lens system arranged as a fourth lens unit, saidfourth lens unit consisting of a front subunit comprising a positivelens component, a positive lens component, a biconcave lens componentand a positive lens component in the order from object side, and a rearsubunit comprising two positive lens components.
 2. A large-aperturezoom lens system according to claim 1 wherein said front subunit of saidfourth lens unit comprises a positive lens component, a positive lenscomponent, a negative lens component and a positive lens component,whereas said rear subunit comprises a positive lens component and apositive lens component, said zoom lens system having the followingnumerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 84.1276                                                             d.sub.1 = 1.1600                                                                              n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                               r.sub.2 = 29.0902                                                             d.sub.2 = 7.3000                                                                              n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                               r.sub.3 = -273.1915                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.7778                                                             d.sub.4 = 5.6000                                                                              n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                               r.sub.5 = 203.0683                                                            d.sub.5 = 0.6000˜8.838˜14.867                                     r.sub.6 = 29.7145                                                             d.sub.6 = 1.0400                                                                              n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                               r.sub.7 = 11.3398                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -21.5403                                                            d.sub.8 = 1.0400                                                                              n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                               r.sub.9 = 15.9303                                                             d.sub.9 = 3.1000                                                                              n.sub.6  = 1.84666                                                                         ν.sub.6 = 23.88                               r.sub.10 = 1554.6274                                                          d.sub.10 = 12.9984˜5.073˜2.828                                    r.sub.11 = -14.7944                                                           d.sub.11 = 1.0000                                                                             n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                               r.sub.12 = -36.0319                                                           d.sub.12 = 4.9325˜4.598˜0.854                                     r.sub.13 = 50.3787                                                            d.sub.13 = 2.6753                                                                             n.sub.8 = 1.74950                                                                          ν.sub.8 = 35.27                               r.sub.14 = -29.8033                                                           d.sub.14 = 0.6469                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 20.2193                                                            d.sub.16 = 5.3125                                                                             n.sub.9 = 1.69350                                                                          ν.sub.9 = 53.23                               r.sub.17 = -440.8891                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -25.3662                                                           d.sub.18 = 1.4008                                                                             n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                              r.sub.19 = 18.0976                                                            d.sub. 19 = 1.8984                                                            r.sub.20 = 104.9452                                                           d.sub.20 = 3.0000                                                                             n.sub.11 = 1.56873                                                                         ν.sub.11 = 63.16                              r.sub.21 = -33.8872                                                           d.sub.21 = 6.0137                                                             r.sub.22 = -1877.6563                                                         d.sub.22 = 3.6497                                                                             n.sub.12 = 1.48749                                                                         ν.sub.12 = 70.15                              r.sub.23 = -18.1673                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 27.7264                                                            d.sub.24 = 3.3156                                                                             n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                              r.sub.25 = -111.3847                                                          l/f.sub.IV = 1.642, D/f.sub.IV = 0.237, f.sub.W /f.sub.A = -0.221             f.sub.IVa /f.sub.S = 1.186, f.sub.IVan /f.sub.S = -0.507                      f.sub.I /f.sub.W = 2.996, f.sub.II /f.sub.W = -1.098, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 - ν .sub.6 = 29.35, n.sub.IVn = 1.84666, f.sub.B = 23.3         ν.sub.IVap - ν.sub.IVbp = -19.597, t.sub.B /f.sub.S                     ______________________________________                                        = 0.2928                                                                  

wherein the reference symbols r₁ through r₂₅ represent radii ofcurvature on the surfaces of the respective lens elements, the rererencesymbols d₁ through d₂₄ designate thicknesses of the respective lenselements and airspaces reserved therebetween, the reference symbols n₁through n₁₃ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₃ represent Abbe's numbers of therespective lens elements.
 3. A large-aperture zoom lens system accordingto claim 1 wherein said front subunit of said fourth lens unit comprisesa positive lens component, a positive lens component, a negative lenscomponent and a positive lens component, whereas said rear subunitcomprises a positive lens component and a positive lens component, saidzoom lens system having the following numerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 82.8380                                                             d.sub.1 = 1.1600                                                                              n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                               r.sub.2 = 28.9584                                                             d.sub.2 = 7.3000                                                                              n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                               r.sub.3 = -243.9195                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.9601                                                             d.sub.4 = 5.6000                                                                              n.sub.3 = 1.62374                                                                          ν.sub.3 = 47.10                               r.sub.5 = 203.8797                                                            d.sub.5 = 0.6000˜8.647˜14.529                                     r.sub.6 = 29.0358                                                             d.sub.6 = 1.0400                                                                              n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                               r.sub.7 = 11.4509                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -21.5434                                                            d.sub.8 = 1.0400                                                                              n.sub.5 = 1.69680                                                                          ν.sub.5 = 55.52                               r.sub.9 = 16.1419                                                             d.sub.9 = 3.1000                                                                              n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                               r.sub.10 = 327.0857                                                           d.sub.10 = 12.7201˜4.953˜2.849                                    r.sub.11 = -15.1829                                                           d.sub.11 = 1.0000                                                                             n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                               r.sub.12 = -38.3036                                                           d.sub.12 = 4.8880˜4.594˜0.854                                     r.sub.13 = 50.2085                                                            d.sub.13 = 2.6726                                                                             n.sub.8 = 1.76200                                                                          ν.sub.8 = 40.10                               r.sub.14 = -29.8907                                                           d.sub.14 = 0.6433                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 20.1914                                                            d.sub.16 = 5.5367                                                                             n.sub.9 = 1.69680                                                                          ν.sub.9 = 55.52                               r.sub.17 = 2178.6990                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -25.1867                                                           d.sub.18 = 1.4025                                                                             n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                              r.sub.19 = 18.2541                                                            d.sub. 19 = 1.8967                                                            r.sub.20 = 89.3959                                                            d.sub.20 = 3.0000                                                                             n.sub.11 = 1.62041                                                                         ν.sub.11 = 60.27                              r.sub.21 = -41.7577                                                           d.sub.21 = 6.1391                                                             r.sub.22 = -2160.7673                                                         d.sub.22 = 3.6490                                                                             n.sub.12 = 1.56873                                                                         ν.sub.12 = 63.16                              r.sub.23 = -20.1024                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 28.7875                                                            d.sub.24 = 3.3002                                                                             n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                              r.sub.25 = -98.5889                                                           l/f.sub.IV = 1.752, D/f.sub.IV = 0.258, f.sub.W /f.sub.A = -0.253             f.sub.IVa /f.sub.S = 1.180, f.sub.IVan /f.sub.S = -0.508                      f.sub.I /f.sub.W = 2.951, f.sub.II /f.sub.W = -1.068, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.14986, n.sub.5 = 1.69680                                ν.sub.5 -  ν.sub.6 = 31.64, n.sub.IVn = 1.84666, f.sub.B = 23.3         ν.sub.IVap - ν.sub.IVbp = -14.692, t.sub.B /f.sub.S                     ______________________________________                                        = 0.2921                                                                  

wherein the reference symbols r₁ through r₂₅ represent radii ofcurvature on the surfaces of the respective lens elements, the referencesymbols d₁ through d₂₄ designate thicknesses of the respective lenselements and airspaces reserved therebetween the reference symbols n₁through n₁₃ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₃ represent Abbe's nubmers of therespective lens elements.
 4. A large-aperture zoom lens system accordingto claim 1 wherein said front subunit of said fourth lens unit comprisesa positive lens component, a positive lens component, a negative lenscomponent and a positive lens component, whereas said rear subunitcomprises a positive lens component and a positive lens component, saidzoom lens system having the following numerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 83.0383                                                             d.sub.1 = 1.1600                                                                              n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                               r.sub.2 = 29.1400                                                             d.sub.2 = 7.3000                                                                              n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                               r.sub.3 = -253.1450                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.6874                                                             d.sub.4 = 5.6000                                                                              n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                               r.sub.5 = 210.2929                                                            d.sub.5 = 0.6000˜8.638˜14.534                                     r.sub.6 = 30.3630                                                             d.sub.6 = 1.0400                                                                              n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                               r.sub.7 = 11.3638                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -21.4761                                                            d.sub.8 = 1.0400                                                                              n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                               r.sub.9 = 17.0207                                                             d.sub.9 = 3.1000                                                                              n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                               r.sub.10 = 1069.1825                                                          d.sub.10 = 13.0418˜5.272˜2.789                                    r.sub.11 = -14.1675                                                           d.sub.11 = 1.0000                                                                             n.sub.7 = 1.69670                                                                          ν.sub.7 = 55.52                               r.sub.12 = -36.2700                                                           d.sub.12 = 4.5289˜4.243˜0.854                                     r.sub.13 = 55.6389                                                            d.sub.13 = 2.6729                                                                             n.sub.8 = 1.74950                                                                          ν.sub.8 = 35.27                               r.sub.14 = -31.9536                                                           d.sub.14 = 0.6353                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 21.0858                                                            d.sub.16 = 5.0173                                                                             n.sub.9 = 1.69350                                                                          ν.sub.9 = 53.23                               r.sub.17 = -708.9650                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -27.0343                                                           d.sub.18 = 1.4021                                                                             n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                              r.sub.19 = 19.1950                                                            d.sub.19 = 1.9053                                                             r.sub.20 = 45.3739                                                            d.sub.20 = 3.0000                                                                             n.sub.11 = 1.65873                                                                         ν.sub.11 = 63.16                              r.sub.21 = -24.8871                                                           d.sub.21 = 6.6760                                                             r.sub.22 = -119.5541                                                          d.sub.22 = 3.6491                                                                             n.sub.12 = 1.48749                                                                         ν.sub.12 = 70.15                              r.sub.13 = -20.3750                                                           d.sub.13 = 0.1342                                                             r.sub.24 = 28.5509                                                            d.sub.24 = 3.3004                                                                             n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                              r.sub.25 = -144.4908                                                          l/f.sub.IV = 1.863, D/f.sub.IV = 0.296, f.sub.W /f.sub.A = -0.016             f.sub.IVa /f.sub.S = 1.071, f.sub.IVan /f.sub.S = -0.539                      f.sub.I /f.sub.W = 2.939, f.sub.II /f.sub.W = -1.071, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 -  ν.sub.6 = 29.35, f.sub.IVn = 1.84666, f.sub.B = 23.3         ν.sub.IVap - ν.sub.IVbp = -19.597, t.sub.B /f.sub.S                     ______________________________________                                        = 0.2921                                                                  

wherein the reference symbols r₁ through r₂₅ represent radii ofcurvature on the surfaces of the respective lens elements, the referencesymbols d₁ through d₂₄ designate thicknesses of the respective lenselements and airspaces reserved therebetween the reference symbols n₁through n₁₃ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₃ represent Abbe's nubmers of therespective lens elements.
 5. A large-aperture zoom lens system accordingto claim 1 wherein said front subunit of said fourth lens unit comprisesa positive lens component, a positive lens component, a negative lenscomponent and a positive lens component, whereas said rear subunitcomprises a positive lens component and a positive lens component, saidzoom lens system having the following numerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 82.6129                                                             d.sub.1 = 1.1600                                                                              n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                               r.sub.2 = 29.2181                                                             d.sub.2 = 7.3000                                                                              n.sub.2 = 1.62012                                                                          ν.sub.2 = 49.66                               r.sub.3 = -246.0953                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.4664                                                             d.sub.4 = 5.6000                                                                              n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                               r.sub.5 = 217.2658                                                            d.sub.5 = 0.6000˜8.516˜14.296                                     r.sub.6 = 34.0022                                                             d.sub.6 = 1.0400                                                                              n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                               r.sub.7 = 11.4972                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -20.9945                                                            d.sub.8 = 1.0400                                                                              n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                               r.sub.9 = 16.3829                                                             d.sub.9 = 3.1000                                                                              n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                               r.sub.10 = 646.6454                                                           d.sub.10 = 12.8886˜5.006˜2.865                                    r.sub.11 = -14.2623                                                           d.sub.11 = 1.0000                                                                             n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                               r.sub.12 = -30.9806                                                           d.sub.12 = 4.5293˜4.484˜0.854                                     r.sub.13 = 50.7675                                                            d.sub.13 = 2.6656                                                                             n.sub.8 = 1.74950                                                                          ν.sub.8 = 35.27                               r.sub.14 = -30.6539                                                           d.sub.14 = 0.5921                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 19.1840                                                            d.sub.16 = 4.5518                                                                             n.sub.9 = 1.69350                                                                          ν.sub.9 = 53.23                               r.sub.17 = 3649.8366                                                          d.sub.17 = 0.8000                                                             r.sub.18 = -24.4207                                                           d.sub.18 = 1.4073                                                                             n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                              r.sub.19 = 18.4904                                                            d.sub. 19 = 3.8044                                                            r.sub.20 = 80.9804                                                            d.sub.20 = 3.0000                                                                             n.sub.11 = 1.56873                                                                         ν.sub.11 = 63.16                              r.sub.21 = -23.6744                                                           d.sub.21 = 4.3200                                                             r.sub.22 = -81.0091                                                           d.sub.22 = 3.6442                                                                             n.sub.12 = 1.48749                                                                         ν.sub.12 = 70.15                              r.sub.23 = -19.6764                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 28.3524                                                            d.sub.24 = 3.3101                                                                             n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                              r.sub.25 = -150.6774                                                          l/f.sub.IV = 1.771, D/f.sub.IV = 0.184, f.sub.W /f.sub.A = 0.010              f.sub.IVa /f.sub.S = 1.095, f.sub.IVan /f.sub.S = -0.505                      f.sub.I /f.sub.W = 2.894, f.sub.II /f.sub.W = -1.021, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350,                               ν.sub.5 - ν.sub. 6 = 29.35, n.sub.IVn = 1.84666, f.sub.B = 23.3         ν.sub.IVap - ν.sub.IVbp = -19.597, t.sub.B /f.sub.S                     ______________________________________                                        = 0.2923                                                                  

wherein the reference symbols r₁ through r₂₅ represent radii ofcurvature on the surfaces of the respective lens elements, the referencesymbols d₁ through d₂₄ designate thicknesses of the respective lenselements and airspaces reserved therebetween, the reference symbols n₁through n₁₃ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₃ represent Abbe's numbers of therespective lens elements.
 6. A large aperture zoom lens systemcomprising a varifocal subsystem comprising a first lens unit having apositive focal length and being immovable for varying focal length ofsaid zoom lens system as a whole, a second variator lens unit having anegative focal length and being movable for varying focal length of thezoom lens system as a whole, and a third compensator lens unit having anegative focal length and functioning mainly for compensating variationof the image position caused by the variation of the focal length ofsaid zoom lens system as a whole, and a relay lens system arranged as afourth lens unit, said fourth lens unit consisting of a front subunitcomprising a positive lens component, a positive lens component and anegative lens component having an object side surface with a radius ofcurvature smaller than the radius of curvature on the image sidesurface, and a rear subunit comprising a negative lens component havingan image side surface with a radius of curvature smaller than the radiusof curvature on the object side surface and two positive lenscomponents.
 7. A large-aperture zoom lens system according to claim 6wherein said front subunit of said fourth lens unit comprises a positivelens component, a positive lens component and a negative lens component,whereas said rear subunit comprises a negative lens component, apositive lens component and a positive lens component, said zoom lenssystem having the following numerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 73.7446                                                             d.sub.1 = 1.1600                                                                              n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                               r.sub.2 = 29.0371                                                             d.sub.2 = 7.3000                                                                              n.sub.2 = 1.62280                                                                          ν.sub.2 = 57.06                               r.sub.3 = -142.5789                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 29.7376                                                             d.sub.4 = 5.6000                                                                              n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                               r.sub.5 = 187.5263                                                            d.sub.5 = 0.6000˜8.158˜13.563                                     r.sub.6 = 761.2471                                                            d.sub.6 = 1.0400                                                                              n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                               r.sub.7 = 12.6032                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -19.9311                                                            d.sub.8 = 1.0400                                                                              n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                               r.sub.9 = 14.4310                                                             d.sub.9 = 3.1000                                                                              n.sub.6 = 1.84666                                                                          ν.sub.6 = 23.88                               r.sub.10 = -537.6964                                                          d.sub.10 = 14.1628˜4.601˜3.099                                    r.sub.11 = -23.9031                                                           d.sub.11 = 1.0000                                                                             n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                               r.sub.12 = -49.2275                                                           d.sub.12 = 2.7690˜4.810˜0.854                                     r.sub.13 = 83.5278                                                            d.sub.13 = 2.6697                                                                             n.sub.8 = 1.73400                                                                          ν.sub.8 = 51.49                               r.sub.14 = -26.0628                                                           d.sub.14 = 0.6362                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 22.6911                                                            d.sub.16 = 3.1050                                                                             n.sub.9 = 1.69680                                                                          ν.sub.9 = 55.52                               r.sub.17 = 205.0173                                                           d.sub.17 = 1.2990                                                             r.sub.18 = -23.8698                                                           d.sub.18 = 1.0000                                                                             n.sub.10 = 1.85666                                                                         ν.sub.10 = 23.88                              r.sub.19 = - 199.2548                                                         d.sub.19 = 8.6005                                                             r.sub.20 = 152.2247                                                           d.sub.20 = 1.0000                                                                             n.sub.11 = 1.80518                                                                         ν.sub.11 = 25.43                              r.sub.21 = 26.2448                                                            d.sub.21 = 1.9319                                                             r.sub.22 = 120.3715                                                           d.sub.22 = 4.7975                                                                             n.sub.12 = 1.56873                                                                         ν.sub.12 = 63.16                              r.sub.23 = -19.9767                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 23.9392                                                            d.sub.24 = 4.6311                                                                             n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                              r.sub.25 = -72.0532                                                           l/f.sub.IV = 1.826, D/f.sub.IV = 0.346, f.sub.W /f.sub.A = 0.057              f.sub.I /f.sub.W = 2.717, f.sub.II /f.sub.W = -0.851, n.sub.4 = 1.73400       n.sub.6 - n.sub.5 = 0.15316, n.sub.5 = 1.69350                                ν.sub.5 - ν.sub.6 = 29.35, n.sub.IVn = 1.82592,                         ν.sub.IVap -  ν.sub.IVbp = -13.15, f.sub.B = 0.95f.sub.S                ______________________________________                                    

wherein the reference symbols r₁ through r₂₅ represent radii ofcurvature on the surfaces of the respective lens elements, the referencesymbols d₁ through d₂₄ designate thicknesses of the respective lenselements and airspaces reserved therebetween, the reference symbols n₁through n₁₃ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₃ represent Abbe's numbers of therespective lens elements.
 8. A large-aperture zoom lens system accordingto claim 6 wherein said front subunit of said fourth lens unit comprisesa positive lens component, a positive lens component and a negative lenscomponent, whereas said rear subunit comprises a negative lenscomponent, a positive lens component, a positive lens component and apositive lens component, said zoom lens system having the followingnumerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 73.4599                                                             d.sub.1 = 1.1600                                                                              n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                               r.sub.2 = 29.7582                                                             d.sub.2 = 7.3000                                                                              n.sub.2 = 1.62280                                                                          ν.sub.2 = 57.06                               r.sub.3 = -143.3946                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 29.8304                                                             d.sub.4 = 5.6000                                                                              n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                               r.sub.5 = 193.5783                                                            d.sub.5 = 0.6000˜8.068˜13.415                                     r.sub.6 = -249.6054                                                           d.sub.6 = 1.0400                                                                              n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                               r.sub.7 = 13.4290                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -22.3190                                                            d.sub.8 = 1.0400                                                                              n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                               r.sub.9 = 13.6545                                                             d.sub.9 = 3.1000                                                                              n.sub. 6 = 1.84666                                                                         ν.sub.6 = 23.88                               r.sub.10 = 395.1326                                                           d.sub.10 = 13.8889˜4.363˜3.225                                    r.sub.11 = -29.6120                                                           d.sub.11 = 1.0000                                                                             n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                               r.sub.12 = -74.5434                                                           d.sub.12 = 3.0371˜5.106˜0.854                                     r.sub.13 = 103.8661                                                           d.sub.13 = 2.6656                                                                             n.sub.8 = 1.72916                                                                          ν.sub.8 = 54.68                               r.sub.14 = -26.8147                                                           d.sub.14 = 0.5983                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 24.1544                                                            d.sub.16 = 3.7803                                                                             n.sub.9 = 1.69680                                                                          ν.sub.9 = 55.52                               r.sub.17 = 586.5944                                                           d.sub.17 = 1.2984                                                             r.sub.18 = -21.4118                                                           d.sub.18 = 1.0000                                                                             n.sub.10 = 1.84666                                                                         ν.sub.10 = 23.88                              r.sub.19 = - 175.5530                                                         d.sub.19 = 6.6556                                                             r.sub.20 = 78.7259                                                            d.sub.20 = 1.0000                                                                             n.sub.11 = 1.80518                                                                         ν.sub.11 = 25.43                              r.sub.21 = 33.7443                                                            d.sub.21 = 1.9815                                                             r.sub.22 = -76.7912                                                           d.sub.22 = 3.8000                                                                             n.sub.12 = 1.48749                                                                         ν.sub.12 = 70.15                              r.sub.23 = -17.6494                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 51.5682                                                            d.sub.24 = 3.0000                                                                             n.sub.13 = 1.48749                                                                         ν.sub.13 = 70.15                              r.sub.25 = -54.5234                                                           d.sub.25 = 0.1500                                                             r.sub.26 = 33.6811                                                            d.sub.26 = 3.7439                                                                             n.sub.14 = 1.48749                                                                         ν.sub.14 = 70.15                              r.sub.27 = 306.4734                                                           l/f.sub.IV = 1.907, D/f.sub.IV = 0.284, f.sub.W /f.sub.A = -0.078             f.sub.I /f.sub.W = 2.696, f.sub.II /f.sub.W = -0.844, n.sub.4 = 1.73400       n.sub.6  - n.sub.5 = 0.15316, n.sub.5 = 1.69350                               ν.sub.5 - ν.sub.6 = 29.35, n.sub.IVn = 1.82592                          ν.sub.IVap - ν.sub.IVbp = -15.05, f.sub.B = 0.95f.sub.S                 ______________________________________                                    

wherein the reference symbols r₁ through r₂₇ represent radii ofcurvature on the surfaces of the respective lens elements, the referencesymbols d₁ through d₂₆ designate thicknesses of the respective lenselements and airspaces reversed therebetween, the reference symbols n₁through n₁₄ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₄ represent Abbe's numbers of therspective lens elements.
 9. A large-aperture zoom lens system accordingto claim 1 wherein distance l as measured from the rear focal point ofsaid zoom lens system as a whole to the rear principal point of thenegative lens component arrange in the most image side of the frontsubunit of said fourth lens unit satisfies the following condition (1):

    1.5f.sub.IV <l<2.2f.sub.IV                                 ( 1)

wherein the reference symbol f_(IV) represents focal length of saidfourth lens unit.
 10. A large-aperture zoom lens system according toclaim 9 wherein airspace D reserved between the front and rear subunitsin said fourth lens unit satisfies the following condition (2):

    0.14f.sub.IV <D<0.5f.sub.IV                                ( 2).


11. A large-aperture zoom lens system according to claim 10 wherein thesystem ranging from said first lens unit to the front subunit of saidfourth lens unit forms a nearly afocal system, said zoom lens systembeing so designed as to satisfy the following condition (3):

    -0.3<f.sub.W /f.sub.A <0.3                                 (3)

wherein the reference symbol f_(W) represents the shortest focal lengthof said zoom lens system as a whole and the reference symbol f_(A)designates total focal length of the system ranging from said first lensunit to said fourth lens unit.
 12. A large-aperture zoom lens systemaccording to claim 11 satisfying the following conditions (4) and (5):

    2.5f.sub.W <f.sub.I <3.5f.sub.W                            ( 4)

    -1.2f.sub.W <f.sub.II <-0.8f.sub.W                         ( 5)

wherein the reference symbol f_(I) represents focal length of said firstlens unit and the reference symbol f_(II) designates focal length ofsaid second lens unit.
 13. A large-aperture zoom lens system accordingto claim 11 so adapted as to be focused on an object located at a veryshort distance by shifting the rear subunit of said fourth lens unit.14. A large-aperture zoom lens system according to claim 13 satisfyingthe following conditions (12) through (14):

    0.5f.sub.S <f.sub.IVa <1.6f.sub.S                          ( 12)

    0.42f.sub.S <|f.sub.IVan |<0.64f.sub.S   ( 13)

    t.sub.B <0.45f.sub.S                                       ( 14)

wherein the reference symbol f_(IVa) represents focal length of thefront subunit of said fourth lens group, the reference symbol f_(IVan)designates focal length of the negative lens component arranged in saidfront subunit, the reference symbol f_(S) denotes a geometrical mean ofthe shortest focal length and the longest focal length of said zoom lenssystem as a whole, and the reference symbol t_(B) represents distance asmeasured from the extreme object side surface to the extreme image sidesurface of the rear subunit of said fourth lens unit.
 15. Alarge-aperture zoom lens system according to claim 12 wherein said firstlens unit comprises a positive cemented doublet comprising a negativemeniscus lens element and a biconvex lens element, and a positivemeniscus lens component, said second lens unit comprises a negativemeniscus lens component, and a negative cemented doublet comprising abiconcave lens element and a positive lens element, and said third lensunit comprises a negative lens component, said zoom lens system being sodesigned as to satisfy the following conditions (6) through (9):

    1.7<n.sub.4                                                ( 6)

    0.05<n.sub.6 -n.sub.5                                      ( 7)

    1.6<n.sub.5                                                ( 8)

    13<ν.sub.5 -ν.sub.6                                  ( 9)

wherein the reference symbol n₄ represents refractive index of thenegative meniscus lens component arranged in said second lens unit, thereference symbols n₅ and n₆ designate refractive indices of thebiconcave lens element and positive lens element respectively of thecemented doublet arranged in said second lens unit, and the referencesymbols ν₅ and ν₆ denote Abbe's numbers of the biconcave lens elementand positive lens element of the cemented doublet arranged in saidsecond lens unit.
 16. A large-aperture zoom lens system according toclaim 15 satisfying the following conditions (10) and (11):

    1.78<n.sub.IVn                                             ( 10)

    ν.sub.IVap <ν.sub.IVbp                               ( 11)

wherein the reference symbol n_(IVn) represents a mean refractive indexof the negative lens components arranged in said fourth lens unit, thereference symbol ν_(IVap) designates a mean Abbe's number of thepositive lens components arranged in the front subunit of said fourthlens unit and the reference symbol ν_(IVbp) denotes a mean Abbe's numberof the positive lens components arranged in the rear subgroup of saidfourth lens unit.
 17. A large-aperture zoom lens system according toclaim 16 so adapted as to be focused on an object located at a veryshort distance by shifting the rear subunit of said fourth lens unit.18. A larger aperture zoom lens system comprising a varifocal subsystemcomprising a first lens unit having a positive focal length and beingimmovable for varying focal length of said zoom lens system as a whole,a second variator lens unit having a negative focal length and beingmovable for varying focal length of the zoom lens system as a whole, anda third compensator lens unit having a negative focal length andfunctioning mainly for compensating variation of the image positioncaused by the variation of the focal length of said zoom lens system asa whole, and a relay lens system arranged as a fourth lens unit, saidfirst lens unit comprising a positive cemented doublet comprising anegative meniscus lens element and a biconvex lens element, and apositive meniscus lens component, said second lens unit comprising anegative meniscus lens component, and a negative cemented doubletcomprising a biconcave lens element and a positive lens element, saidthird lens unit comprises a negative lens component and said fourth lensunit consisting of a front sub-unit comprising a positive lenscomponent, a positive lens component, a positive lens component and anegative lens component, and a rear sub-unit comprising a positive lenscomponent and a positive lens component, said zoom lens system havingthe following numerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 145.4589                                                            d.sub.1 = 1.1600                                                                             n.sub.1 = 1.80518                                                                           ν.sub.1 = 25.43                               r.sub.2 = 28.8038                                                             d.sub.2 = 7.3000                                                                             n.sub.2 = 1.62012                                                                           ν.sub.2 = 49.66                               r.sub.3 = -124.4191                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 28.0380                                                             d.sub.4 = 5.6000                                                                             n.sub.4 = 1.62045                                                                           ν.sub.3 = 38.12                               r.sub.5 = 194.2344                                                            d.sub.5 = 0.6000˜9.404˜16.075                                     r.sub.6 = 27.2667                                                             d.sub.6 = 1.0400                                                                             n.sub.4 = 1.78590                                                                           ν.sub.4 = 44.18                               r.sub.7 = 10.3892                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -15.8056                                                            d.sub.8 = 1.0400                                                                             n.sub.5 = 1.70154                                                                           ν.sub.5 = 41.21                               r.sub.9 = 13.5487                                                             d.sub.9 = 3.4000                                                                             n.sub.6 = 1.84666                                                                           ν.sub.6 = 23.88                               r.sub.10 = -92.7796                                                           d.sub.10 = 17.4871˜8.204˜2.434                                    r.sub.11 = -11.9646                                                           d.sub.11 = 1.0000                                                                            n.sub.7 = 1.71300                                                                           ν.sub.7 = 53.84                               r.sub.12 = -42.5665                                                           d.sub.12 = 1.2558˜1.725˜0.855                                     r.sub.13 = -85.6664                                                           d.sub.13 = 2.7002                                                                            n.sub.8 = 1.59270                                                                           ν.sub.8 = 35.29                               r.sub.14 = -17.9449                                                           d.sub.14 = 0.8553                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 21.1736                                                            d.sub.16 = 4.5115                                                                            n.sub.9 = 1.62230                                                                           ν.sub.9 = 53.20                               r.sub.17 = -27.2639                                                           d.sub.17 = 0.2100                                                             r.sub.18 = 14.3135                                                            d.sub.18 = 3.1600                                                                            n.sub.10 = 1.51742                                                                          ν.sub.10 = 52.41                              r.sub.19 =  115.7820                                                          d.sub.19 = 1.2000                                                             r.sub.20 = -25.5498                                                           d.sub.20 = 1.6617                                                                            n.sub.11 = 1.84666                                                                          ν.sub.11 = 23.88                              r.sub.21 = 15.2150                                                            d.sub.21 = 8.5579                                                             r.sub.22 = 2332.0237                                                          d.sub.22 = 4.2478                                                                            n.sub.12 = 1.51112                                                                          ν.sub.12 = 60.48                              r.sub.23 = -20.8501                                                           d.sub.23 = 0.1342                                                             r.sub.24 = 33.8590                                                            d.sub.24 = 4.6445                                                                            n.sub.13 = 1.48749                                                                          ν.sub.13 = 70.15                              r.sub.25 = -61.6882                                                           l/f.sub.IV = 1.852, D/f.sub.IV = 0.385, f.sub.W /f.sub.A = -0.197             f.sub.IVa /f.sub.S = 0.667, f.sub.IVan /f.sub.S = -0.456                      f.sub.I /f.sub.W = 3.061, f.sub.II /f.sub.W = -0.999, n.sub.4 = 1.78590       n.sub.6 - n.sub.5 = 0.14512, n.sub.5 = 1.70154,                               ν.sub.5 -  ν.sub.6 = 17.33, n.sub.IVn = 1.84666, f.sub.B = 23.3         ν.sub.IVap - ν.sub.IVbp = -18.348, t.sub.B /f.sub.S                     ______________________________________                                        = 0.3722                                                                  

wherein the reference symbols r₁ through r₂₅ represent radii ofcurvature on the surfaces of the respective lens elements, the referencesymbols d₁ through d₂₄ designate thicknesses of the respective lenselements and airspaces reserved therebetween, the reference symbols n₁through n₁₃ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₃ represent Abbe's numbers of therespective lens elements.
 19. A large aperture zoom lens systemcomprising a varifocal subsystem comprising a first lens unit having apositive focal length and being immovable for varying focal length ofsaid zoom lens system as a whole, a second variator lens unit having anegative focal length and being movable for varying focal length of thezoom lens system as a whole, and a third compensator lens unit having anegative focal length and functioning mainly for compensating variationof the image position caused by the variation of the focal length ofsaid zoom lens system as a whole, and a relay lens system arranged as afourth lens unit, said first lens unit comprises a positive cementeddoublet comprising a negative meniscus lens element and a biconvex lenselement, and a positive meniscus lens component, said second lens unitcomprising a negative meniscus lens component, and a negative cementeddoublet comprising a biconcave lens element and a positive lens element,said third lens unit comprising a negative lens component, and saidfourth lens unit consisting of a front sub-unit comprising a positivelens component, a positive lens component and a negative lens component,and a rear sub-unit comprising a negative lens component, a positivelens component and a positive lens component, said zoom lens systemhaving the following numerical data:

    ______________________________________                                        f = 14˜24.25˜42                                                   ______________________________________                                        r.sub.1 = 73.1407                                                             d.sub.1 = 1.1600                                                                              n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                               r.sub.2 = 29.2813                                                             d.sub.2 = 7.3000                                                                              n.sub.2 = 1.62280                                                                          ν.sub.2 = 57.06                               r.sub.3 = -142.5699                                                           d.sub.3 = 0.1700                                                              r.sub.4 = 29.4855                                                             d.sub.4 = 5.6000                                                                              n.sub.3 = 1.62012                                                                          ν.sub.3 = 49.66                               r.sub.5 = 188.5203                                                            d.sub.5 = 0.6000˜8.038˜13.370                                     r.sub.6 = -2148.9531                                                          d.sub.6 = 1.0400                                                                              n.sub.4 = 1.73400                                                                          ν.sub.4 = 51.49                               r.sub.7 = 12.7344                                                             d.sub.7 = 3.9500                                                              r.sub.8 = -19.2458                                                            d.sub.8 = 1.0400                                                                              n.sub.5 = 1.69350                                                                          ν.sub.5 = 53.23                               r.sub.9 = 14.4976                                                             d.sub.9 = 3.1000                                                                              n.sub. 6 = 1.84666                                                                         ν.sub.6 = 23.88                               r.sub.10 = -336.4032                                                          d.sub.10 = 14.0324˜5.201˜2.643                                    r.sub.11 = -21.0833                                                           d.sub.11 = 1.0000                                                                             n.sub.7 = 1.69680                                                                          ν.sub.7 = 55.52                               r.sub.12 = -51.2968                                                           d.sub.12 = 2.3119˜3.735˜0.854                                     r.sub.13 = 103.8053                                                           d.sub.13 = 2.6678                                                                             n.sub.8 = 1.72916                                                                          ν.sub.8 = 54.68                               r.sub.14 = -34.5149                                                           d.sub.14 = 0.6169                                                             r.sub.15 = ∞ (stop)                                                     d.sub.15 = 2.0000                                                             r.sub.16 = 52.1018                                                            d.sub.16 = 3.3386                                                                             n.sub.9 = 1.69680                                                                          ν.sub.9 = 55.52                               r.sub.17 = -58.1766                                                           d.sub.17 = 0.1500                                                             r.sub.18 = 30.8549                                                            d.sub.18 = 3.0000                                                                             n.sub.10 = 1.69680                                                                         ν.sub.10 = 55.52                              r.sub.19 =  90.7813                                                           d.sub.19 = 1.3000                                                             r.sub.20 = -24.0593                                                           d.sub.20 = 1.0000                                                                             n.sub.11 = 1.84666                                                                         ν.sub.11 = 23.88                              r.sub.21 = -184.3586                                                          d.sub.21 = 5.8297                                                             r.sub.22 = 136.6332                                                           d.sub.22 = 1.0000                                                                             n.sub.12 = 1.80518                                                                         ν.sub.12 = 25.43                              r.sub.23 = 27.4732                                                            d.sub.23 = 1.9396                                                             r.sub.24 = 178.2794                                                           d.sub.24 = 4.7972                                                                             n.sub.13 = 1.56873                                                                         ν.sub.13 = 63.16                              r.sub.25 = -19.8353                                                           d.sub.25 = 0.1342                                                             r.sub.26 = 27.9084                                                            d.sub.26 = 4.6096                                                                             n.sub.14 = 1.48749                                                                         ν.sub.14 = 70.15                              r.sub.27 = -64.6149                                                           l/f.sub.IV = 1.860, D/f.sub.IV = 0.255, f.sub.W /f.sub.A = 0.110              f.sub.I /f.sub.W = 2.685, f.sub.II /f.sub.W = -0.840, n.sub.4 = 1.73400       n.sub.6  - n.sub.5 = 0.15316, n.sub.5 = 1.69350                               ν.sub.5 - ν.sub.6 = 29.35, n.sub.IVn = 1.82592                          ν.sub.IVap - ν.sub.IVbp = -11.415, f.sub.B = 0.95f.sub.S                ______________________________________                                    

wherein the reference symbols r₁ through r₂₇ represent radii ofcurvature on the surfaces of the respective lens elements, the referencesymbols d₁ through d₂₆ designate thicknesses of the respective lenselements and airspaces reserved therebetween, the reference symbols n₁through n₁₄ denote refractive indices of the respective lens elementsand the reference symbols ν₁ through ν₁₄ represents Abbe's numbers ofthe respective lens elements.